Variable capacity oil mist generator



Jan. 1, 1957 F. G. SCHWEISTHAL 2,776,025

VARIABLE CAPACITY OIL MIST GENERATOR Filed Oct. 13, 1953 IN V EN TOR.

@414 ,7/{ ,w9, Amiga 4 I 5:2 & 42

United States PatentO VARIABLE CAPACITY OIL MIST GENERATOR Frederick G. Schweisthal, Skokie, 111., assignor to Stewart- Warner Corporation, Chicago, 111., a corporation of Application October 13, 1953, Serial No. 385,745

4 Claims. (Cl. 184-55) The present invention relates to variable capacity aerosol generators, and more particularly to generators for supplying oil mist for distribution to the bearings and other lubrication points of a machine. In general the lubricating mist or aerosol is formed from oil atomized in a venturi which is supplied with air under a pressure that ordinarily can be regulated to vary the rate at which the mist is produced.

One object of the invention is to provide an improved oil mist generator of the above character in which the proportion of oil to air in the mist generated can be regulated in a highly satisfactory and efficient manner.

A more specific object is to provide in such a mist generator for improved regulation of the oil flow into the mist generating air stream through a controlled inlet of air to modify the efiective suction of the generator venturi.

In conjunction with the previous objects, a further object is to provide for the premixing of clean air with the oil entering the mist generating venturi.

Other objects and advantages will be apparent from the following description of the form of the invention shown in the drawings, in which:

Figure 1 is a vertical view, largely in section, of an oil mist generator incorporating the invention;

Fig. 2 is a fragmentary sectional view taken along the line 2-2 of Fig. 1; and

Fig. 3 is a fragmentary sectional view taken along line 3-3 of Fig. 2 and showing a control assembly for the generator.

The variable capacity mist generator shown comprises a reservoir bolted to the lower end of a downwardly open casting 12 and supplied withoil through an opening 14 in the upper end of the. casting normally closed by a cap 16. A vertical pipe 18 threaded at its upper end into an internal boss 19 on one side of the casting forms a suction passageway from a strainer 20 in the lower end of the reservoir to a reduced pressure space 22 within the boss.

The space 22 adjoins the medial portion only of, an elongated venturi plug member 28 threaded into a horizontal bore in the boss 19 and extending in opposite directions substantially beyond the space 22. An atomizing air inlet 23 formed in the outer end of the venturi member 28 and a mist outlet 25 formed in the inner end of the member are connected by a venturi passageway 27 extending axially through the member and shaped to form in one section 26 of the passageway a space in which the pressure is reduced as an incident to the flow of a stream of air therethrough from the inlet to the outlet. Communication between the reduced pressure space 26 in the venturi passageway 27 and the previously mentioned space 22 is established independently of the atomizing air inlet 23 and the mist outlet 25 by fluid supply bores 24 extending from the venturi passage space 26 radially through the member 28 to connect with the space 22.

Air from a pressure line 30 connected to the casting 12 is supplied to the atomizing air inlet 23 of the pas- 2,776,025 Patented Jan. 1, 1957 sageway 27 through a series of interconnecting bores 32 and a pressure regulator 34 capable of maintaining a predetermined constant pressure in a passageway 35 in the casting 12 suitably connected with the outlet of the pressure regulator and communicating with the inlet 23 of the venturi (the right end as shown in Fig. 1).

As shown, the adjustable regulator 34 comprises a valve 36 threaded into the casting 12 and controlled by suitable regulator structure mounted in an enlarged boss 40.

The pressure of the air supplied to the venturi inlet 23 is indicated by a suitable air gauge 50 mounted in a boss 52 and connected by bores 54 to the outlet from the regulator 34.

The fast moving air stream in the venturi passageway 27 reduces the pressure in venturi space 26 and in the connected space 22, thus drawing oil up through an outlet orifice 55 in the pipe 18 to flow into the venturi air stream through the radial bores 24. The stream of air and atomized oil issuing from the venturi outlet 25 flows around a battle 56 and out through a mist discharge opening 58 in the casting for distribution to bearings through a conduit system such as that shown in the patent to Gothberg et al., No. 2,642,156.

The volumetric rate at which oil mist is generated is determined by regulating the air pressure applied to the venturi inlet 23 thus varying the rate of air flow through the venturi.

A highly effective regulation of the oil flow up through the pipe 18 and into the venturi space 26 is provided by a controlled admission of outside air into the reduced pressure space 22 to modify the eifective suction of the venturi. structurally, the means used for this purpose comprises a vertically elongated body 60 including a stem 62 threaded into a boss 64 on the top of the casting 12. An axial bore in the body 60 forms a passageway 66 opening downwardly into the reduced pressure space 22. The upper end of the passageway 66 merges with the lower end of a downwardly extending counterbore 68 defining with the passageway a valve seat 70 medially located within the body 60.

The efiective flow area of the orifice formed by the valve seat 70 is controlled by a needle valve member 72 threaded into the upper end of the counterbore 68 and secured in adjusted position by a locknut 74. Two inlet passages to the throttling valve thus formed are provided by a bore 76 extending transversely through the body 60 just above the valve seat 70.

An edge type paper filter 78 having a hollow, cylindrical shape encircles the body 60 between an annular shoulder 80 on the upper end of the body and a washer 82 held in place by a snap ring 84 disposed a substantial distance below the transverse bore 76. The section of the body 60 between opposite ends of the filter 78 is turned down to a reduced diameter to form an annular passageway 86 between the outer ends of the bore 76 and the inside of the filter.

In reviewing the operation of the generator thus pro vided, it will be appreciated that for any given rate of air flow through the venturi passageway 27, the venturi will tend to produce a definite pressure drop in its throat 26 and a corresponding diminution of the pressure within the space 22. The rate of oil flow through the pipe 18 and into the venturi varies with the degree of this pressure drop.

Accurate regulation of the rate of oil fiow into the venturi is achieved by a controlled admission of outside air into the space 22 to modify the pressure drop in this space. Thus by adjusting the position of the needle valve 72 in relation to the valve seat 70 the pressure drop within the space 22 can be varied from the maximum suction of the venturi (when the valve is fully closed) to a very minor value (when the valve is fully open, allowing for the free inflowof air-)-.

The incoming air cleaned by the filter 78 is premixed with the oil as it flows through the venturi passages 24 into the atomizing air stream.

While I have shownand described a preferred embodiment of. myinvention, it will be apparent that numerous variations and modifications thereof-mayv be made without departing. from the underlying principles and scope of the invention. I therefore desire by the following claims to include all such variations and modifications by which substantially theresults of my invention maybeobtained through the use of substantially the same or equivalent means.

I claim:

1. In a variable capacity oil mist generator, the combination of means defining a source of oil, a mist generating venturi, means for-supplying air under pressure to said venturi for passage therethrough, means defining a passageway betweensaidoil source and a reduced pressure. section of said venturi, and means for accurately controlling. the rate ofoil flow into said venturi comprising, an elongated bodydefining an air inlet orifice and an air inlet passageway between said orifice and said first mentioned passageway, a valve member mounted in saidbody for-regulating the efiective flow area of said orifice, a cylindrical air filter surrounding-the outer end of said body, andmeans including a transverse bore in said body connecting said filter with the inlet side of said orifice.

2. A variable capacity oil mist generator, comprising, in combination, an oil reservoir, venturi means located above said reservoir and defining an atomizing air inlet and a mist outlet spaced from each other, said venturi means defining a venturi passageway connecting said inlet and said outlet and shaped to define within one section of the passageway a space in which the pressure is reduced'by the venturi etfect of a stream of air flowing through the passageway from said inlet to said outlet, air supply means connected to said inlet for supplying airunder pressure thereto, said venturi means defining afiuid supply bore communicating with said reduced pressure section of said .venturi passageway independently of said inlet and said outlet, means defining asuction passage connecting said oil reservoir to said-fluid supply bore, means defining a regulating orifice, means interconnecting one side of said orifice to said fluid supply bore independently of said venturi passageway, means providing independently of said passageway communication between the opposite side of said orifice and the atmosphere ambient to the generator, regulating means coacting with said orifice to vary the .elfective flow area therethrough, and means. includingmist discharge/means for collecting and discharging oil mist from said mist outlet of said venturi means.

3. Avariable capacity oil mist generator comprising, I

let and a mist outlet spaced from each other, said venturi means defining a venturi passageway connecting said inlet and said outlet and shaped to define within one section of the passageway a space in which the pressure is reduced as an incident to the flow of a stream of air therethrough from said inlet to said outlet, air supply means connected to said venturi inlet for supplying air under pressure thereto, said venturi means defining a fluid supply bore communicating with said reduced pressure section of said venturi passageway independently of. said inlet and said outlet, means, defining a suction passage connecting said oil reservoir to said fluid supply bore, means defining a regulating. orifice, means establishing communication between one side of said orifice and the reduced pressure section of said venturipassageway independently of said inlet and said outlet, the other side of said orifice being exposed to receive air independently of said venturi passageway and of said suction passage, means coacting with said orifice to vary the efiective fiow area therethrough, and means including mist discharge means for collecting and discharging oil. mist issuing:

from said venturi mist outlet.

4. A variable capacity oil mist generator comprising,

of the passageway a space in which the pressure is reducedas an incident to the flow of a stream of air through the passageway from'said inlet to said outlet, air supply means connected to said venturi inlet for supplying air under pressure thereto, said venturi means defining a fluid supply bore communicating with said reduced pressure section of said venturi passageway independently of said'inlet and said outlet, means defining a suction passage connecting said oil reservoir to said fluid supply bore, means defining a regulating orifice, means establishing communication between one side of said orifice and the reduced pressure section of said venturi passageway independently of said inlet and said outlet, means connecting the-opposite side of said orifice tothe atmosphere ambient to said generator, an air filter interposed in said last mentioned connecting means to filter the air passing..therethrough to the orifice, adjustable throttling means coacting with said orifice to regulate the eifective flow area thereof, and means including mist dischargemeans for References Cited in the file of this patent UNITED STATES PATENTS 875,657 Durant Dec. 31, .1907 1,990,524 Bystricky Feb. .12, 19351 2,610,700 Gothberg Sept. 16,. 1952. 2,613,067 Goodyer Oct. 7, 1952 2,672,136 Farrell Mar.: 16,1954 

